For example, Patent Document 1 describes, as a technique applicable to a monitoring camera system, a technique for easily and accurately specifying a tracking target before tracking or during tracking an object. In this technique, the object to be the tracking target is enlarged and displayed and other objects are extracted as tracking target candidates. Only by performing an easy operation of selecting a target (tracking target) that the user wishes to enlarge and display among the extracted tracking target candidates, it becomes possible to obtain a desired enlarged and displayed image (zoom image) (see paragraphs [0010],[0097], etc. in specification of Patent Document 1).
Patent Document 1: Japanese Patent Application Laid-open No. 2009-251940